The present invention relates to a vehicle brake mechanism and more particularly relates to a mechanism having spring-applied, hydraulically-released braking members.
Spring-applied, hydraulically-released braking members are often employed in brake mechanisms intended for use as vehicle park brakes. Heretofore, these mechanisms have suffered from one or more of the following disadvantages:
1. Their braking capacity is not sufficient to prevent the vehicle from being driven with the brake engaged thus leading to undue wear and failure of the brake components. Also, the heat generated in the brake mechanism by such driving presents a fire hazard. PA1 2. The brake members are adversely affected by contact with brake fluid. PA1 3. Emergency braking is too abrupt. PA1 4. Large sealing surfaces are used making the keeping of tolerances difficult. PA1 5. Hydraulic fluid is pressurized by a manually operated pump to release the brake, for permitting towing and the like, in the event of a failure of the primary pressure source and thus complicates the system and makes it less reliable.